diff --git a/package-lock.json b/package-lock.json
index 43a6c6b..764f596 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "goodbuddy",
-  "version": "0.8.3",
+  "version": "0.8.4",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "goodbuddy",
-      "version": "0.8.3",
+      "version": "0.8.4",
       "license": "UNLICENSED",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.30.0",
diff --git a/package.json b/package.json
index cfbe114..b4f27c6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "goodbuddy",
-  "version": "0.8.3",
+  "version": "0.8.4",
   "private": true,
   "description": "Secure desktop AI workspace with controlled Agent Runtimes",
   "desktopName": "GoodBuddy",
diff --git a/src/main/knowledge/embedding-errors.test.ts b/src/main/knowledge/embedding-errors.test.ts
index d6a7a1c..db332cf 100644
--- a/src/main/knowledge/embedding-errors.test.ts
+++ b/src/main/knowledge/embedding-errors.test.ts
@@ -31,6 +31,11 @@ describe('embedding error classification', () => {
         timedOut: true
       }).code
     ).toBe('timeout')
+    const timeout = new Error('Embedding request timed out')
+    timeout.name = 'TimeoutError'
+    expect(
+      classifyEmbeddingError(timeout, { cancelled: true }).code
+    ).toBe('timeout')
   })
 
   it('never returns provider bodies, credentials, endpoints or nested causes', () => {
diff --git a/src/main/knowledge/embedding-errors.ts b/src/main/knowledge/embedding-errors.ts
index f0adf07..5f5c0c0 100644
--- a/src/main/knowledge/embedding-errors.ts
+++ b/src/main/knowledge/embedding-errors.ts
@@ -105,16 +105,22 @@ function classifyCode(
   const text = errorText(error)
   const status = numericStatus(error) ?? statusFromText(text)
 
+  if (error instanceof Error && error.name === 'TimeoutError') {
+    return 'timeout'
+  }
+  if (error instanceof Error && error.name === 'AbortError') {
+    return 'cancelled'
+  }
+  if (options.timedOut) {
+    return 'timeout'
+  }
   if (
     options.cancelled ||
     hasAny(text, ['aborterror', 'aborted', 'cancelled', 'canceled'])
   ) {
     return 'cancelled'
   }
-  if (
-    options.timedOut ||
-    hasAny(text, ['timeout', 'timed out', 'etimedout'])
-  ) {
+  if (hasAny(text, ['timeout', 'timed out', 'etimedout'])) {
     return 'timeout'
   }
   if (
diff --git a/src/main/knowledge/embedding-index-coordinator.test.ts b/src/main/knowledge/embedding-index-coordinator.test.ts
index c247945..ed03246 100644
--- a/src/main/knowledge/embedding-index-coordinator.test.ts
+++ b/src/main/knowledge/embedding-index-coordinator.test.ts
@@ -181,6 +181,89 @@ describe('EmbeddingIndexCoordinator', () => {
     expect(JSON.stringify(result)).not.toContain('private payload')
   })
 
+  it('preserves a provider timeout when the diagnostic signal aborts later', async () => {
+    const repository = new MemoryRepository()
+    const coordinator = new EmbeddingIndexCoordinator(repository)
+    const controller = new AbortController()
+    let rejectProvider:
+      | ((reason?: unknown) => void)
+      | undefined
+    const diagnostic = coordinator.diagnose(
+      provider(
+        () =>
+          new Promise<number[][]>((_resolve, reject) => {
+            rejectProvider = reject
+          })
+      ),
+      { signal: controller.signal }
+    )
+    await vi.waitFor(() => {
+      expect(rejectProvider).toBeDefined()
+    })
+
+    const timeout = new Error('Embedding request timed out')
+    timeout.name = 'TimeoutError'
+    controller.abort()
+    rejectProvider?.(timeout)
+
+    await expect(diagnostic).resolves.toMatchObject({
+      status: 'unavailable',
+      error: {
+        code: 'timeout'
+      }
+    })
+  })
+
+  it('keeps diagnostics independent from an active rebuild cancellation', async () => {
+    const repository = new MemoryRepository()
+    let rebuildSignal: AbortSignal | undefined
+    let resolveDiagnostic: ((vectors: number[][]) => void) | undefined
+    const embed = vi.fn<EmbeddingIndexProvider['embed']>(
+      (input, signal) => {
+        if (input[0] === 'GoodBuddy 向量模型连接测试') {
+          return new Promise<number[][]>((resolve) => {
+            resolveDiagnostic = resolve
+          })
+        }
+        return new Promise<number[][]>((_resolve, reject) => {
+          rebuildSignal = signal
+          signal?.addEventListener(
+            'abort',
+            () => reject(signal.reason),
+            { once: true }
+          )
+        })
+      }
+    )
+    const sharedProvider = provider(embed)
+    const coordinator = new EmbeddingIndexCoordinator(repository, {
+      createId: () => 'job-concurrent'
+    })
+    coordinator.startRebuild(sharedProvider)
+    await vi.waitFor(() => {
+      expect(rebuildSignal).toBeDefined()
+    })
+
+    const diagnostic = coordinator.diagnose(sharedProvider)
+    await vi.waitFor(() => {
+      expect(resolveDiagnostic).toBeDefined()
+    })
+    expect(coordinator.cancel('job-concurrent')).toBe(true)
+    resolveDiagnostic?.([[0.25, 0.5, 0.75]])
+
+    await expect(diagnostic).resolves.toMatchObject({
+      status: 'available',
+      dimensions: 3
+    })
+    await expect(coordinator.waitForCompletion()).resolves.toMatchObject({
+      status: 'cancelled'
+    })
+    expect(embed.mock.calls).toContainEqual([
+      ['GoodBuddy 向量模型连接测试'],
+      undefined
+    ])
+  })
+
   it('replaces each document atomically and persists completed progress', async () => {
     const repository = new MemoryRepository()
     const coordinator = new EmbeddingIndexCoordinator(repository, {
@@ -320,6 +403,42 @@ describe('EmbeddingIndexCoordinator', () => {
     expect(repository.lastJob).toEqual(cancelled)
   })
 
+  it('preserves a provider timeout when rebuild cancellation arrives later', async () => {
+    const repository = new MemoryRepository()
+    const coordinator = new EmbeddingIndexCoordinator(repository, {
+      createId: () => 'job-timeout'
+    })
+    let rejectProvider:
+      | ((reason?: unknown) => void)
+      | undefined
+    coordinator.startRebuild(
+      provider(
+        () =>
+          new Promise<number[][]>((_resolve, reject) => {
+            rejectProvider = reject
+          })
+      )
+    )
+    await vi.waitFor(() => {
+      expect(rejectProvider).toBeDefined()
+    })
+
+    const timeout = new Error('Embedding request timed out')
+    timeout.name = 'TimeoutError'
+    expect(coordinator.cancel('job-timeout')).toBe(true)
+    rejectProvider?.(timeout)
+
+    await expect(coordinator.waitForCompletion()).resolves.toMatchObject({
+      status: 'failed',
+      error: {
+        code: 'timeout'
+      }
+    })
+    expect(repository.errors.get('document-1')).toBe(
+      '向量服务响应超时。'
+    )
+  })
+
   it('marks an interrupted persisted job cancelled during initialization', async () => {
     const repository = new MemoryRepository()
     repository.lastJob = {
diff --git a/src/main/knowledge/embedding-index-coordinator.ts b/src/main/knowledge/embedding-index-coordinator.ts
index 8e28ed2..bc9047a 100644
--- a/src/main/knowledge/embedding-index-coordinator.ts
+++ b/src/main/knowledge/embedding-index-coordinator.ts
@@ -431,13 +431,15 @@ export class EmbeddingIndexCoordinator {
           await this.repository
             .discardDocumentReplacement(replacementId)
             .catch(() => undefined)
-          if (signal.aborted) {
-            throw error
-          }
           const safeError =
             error instanceof EmbeddingOperationError
               ? error.toSafeError()
-              : classifyEmbeddingError(error)
+              : classifyEmbeddingError(error, {
+                  cancelled: signal.aborted
+                })
+          if (safeError.code === 'cancelled') {
+            throw error
+          }
           await this.repository.recordDocumentError(
             document.id,
             provider.provider,
@@ -467,9 +469,13 @@ export class EmbeddingIndexCoordinator {
         }
       })
     } catch (error) {
-      const cancelled =
-        signal.aborted ||
-        classifyEmbeddingError(error).code === 'cancelled'
+      const safeError =
+        error instanceof EmbeddingOperationError
+          ? error.toSafeError()
+          : classifyEmbeddingError(error, {
+              cancelled: signal.aborted
+            })
+      const cancelled = safeError.code === 'cancelled'
       this.updateJob(
         cancelled
           ? {
@@ -479,10 +485,7 @@ export class EmbeddingIndexCoordinator {
           : {
               status: 'failed',
               completedAt: this.now(),
-              error:
-                error instanceof EmbeddingOperationError
-                  ? error.toSafeError()
-                  : classifyEmbeddingError(error)
+              error: safeError
             }
       )
     }
diff --git a/src/main/knowledge/openai-embedding-client.test.ts b/src/main/knowledge/openai-embedding-client.test.ts
index 9365ee9..651ca5c 100644
--- a/src/main/knowledge/openai-embedding-client.test.ts
+++ b/src/main/knowledge/openai-embedding-client.test.ts
@@ -68,6 +68,94 @@ describe('OpenAIEmbeddingClient', () => {
     )
   })
 
+  it('distinguishes its request timeout from caller cancellation', async () => {
+    const waitForAbort = vi.fn<typeof fetch>(
+      async (_input, init) =>
+        new Promise<Response>((_resolve, reject) => {
+          init?.signal?.addEventListener(
+            'abort',
+            () => reject(init.signal?.reason),
+            { once: true }
+          )
+        })
+    )
+    const timedClient = new OpenAIEmbeddingClient({
+      endpoint: 'http://127.0.0.1:11434/v1/embeddings',
+      model: 'nomic-embed-text',
+      timeoutMs: 100,
+      fetch: waitForAbort
+    })
+
+    await expect(
+      timedClient.embed(['safe synthetic input'])
+    ).rejects.toMatchObject({
+      name: 'TimeoutError',
+      message: 'Embedding request timed out'
+    })
+
+    const caller = new AbortController()
+    const cancelled = timedClient.embed(
+      ['safe synthetic input'],
+      caller.signal
+    )
+    caller.abort(new Error('caller cancelled'))
+    await expect(cancelled).rejects.toMatchObject({
+      name: 'AbortError',
+      message: 'Embedding request was cancelled'
+    })
+
+    let rejectTransport:
+      | ((reason?: unknown) => void)
+      | undefined
+    let transportSignal: AbortSignal | null | undefined
+    const delayedTransport = vi.fn<typeof fetch>(
+      async (_input, init) =>
+        new Promise<Response>((_resolve, reject) => {
+          transportSignal = init?.signal
+          rejectTransport = reject
+        })
+    )
+    const delayedClient = new OpenAIEmbeddingClient({
+      endpoint: 'http://127.0.0.1:11434/v1/embeddings',
+      model: 'nomic-embed-text',
+      timeoutMs: 100,
+      fetch: delayedTransport
+    })
+    const lateCaller = new AbortController()
+    const timeoutThenCancellation = delayedClient.embed(
+      ['safe synthetic input'],
+      lateCaller.signal
+    )
+    await vi.waitFor(
+      () => {
+        expect(transportSignal?.aborted).toBe(true)
+        expect(transportSignal?.reason).toMatchObject({
+          name: 'TimeoutError'
+        })
+      },
+      { interval: 5, timeout: 500 }
+    )
+    lateCaller.abort()
+    rejectTransport?.(transportSignal?.reason)
+    await expect(timeoutThenCancellation).rejects.toMatchObject({
+      name: 'TimeoutError',
+      message: 'Embedding request timed out'
+    })
+
+    const preCancelled = new AbortController()
+    preCancelled.abort(new Error('caller cancelled before request'))
+    await expect(
+      delayedClient.embed(
+        ['safe synthetic input'],
+        preCancelled.signal
+      )
+    ).rejects.toMatchObject({
+      name: 'AbortError',
+      message: 'Embedding request was cancelled'
+    })
+    expect(delayedTransport).toHaveBeenCalledTimes(1)
+  })
+
   it('rejects unsafe endpoints and malformed vectors', async () => {
     expect(
       () =>
diff --git a/src/main/knowledge/openai-embedding-client.ts b/src/main/knowledge/openai-embedding-client.ts
index 3147a2d..2c13393 100644
--- a/src/main/knowledge/openai-embedding-client.ts
+++ b/src/main/knowledge/openai-embedding-client.ts
@@ -9,7 +9,8 @@ const MAX_URL_LENGTH = 2_048
 const MAX_DIMENSIONS = 8_192
 const MAX_RESPONSE_BYTES = 16 * 1024 * 1024
 const MIN_TIMEOUT_MS = 100
-const MAX_TIMEOUT_MS = 120_000
+const DEFAULT_TIMEOUT_MS = 120_000
+const MAX_TIMEOUT_MS = DEFAULT_TIMEOUT_MS
 
 export interface OpenAIEmbeddingClientOptions {
   endpoint: string
@@ -64,6 +65,18 @@ function normalizedEndpoint(input: string): string {
   return url.toString()
 }
 
+function embeddingAbortError(
+  requestSignal: AbortSignal,
+  timeoutError: Error
+): Error {
+  if (requestSignal.reason === timeoutError) {
+    return timeoutError
+  }
+  const error = new Error('Embedding request was cancelled')
+  error.name = 'AbortError'
+  return error
+}
+
 async function readBoundedJson(response: Response): Promise<unknown> {
   const declaredLength = response.headers.get('content-length')
   if (
@@ -187,7 +200,7 @@ export class OpenAIEmbeddingClient implements EmbeddingProvider {
       MAX_BATCH_SIZE
     )
     this.timeoutMs = boundedInteger(
-      options.timeoutMs ?? 15_000,
+      options.timeoutMs ?? DEFAULT_TIMEOUT_MS,
       'timeoutMs',
       MIN_TIMEOUT_MS,
       MAX_TIMEOUT_MS
@@ -255,11 +268,19 @@ export class OpenAIEmbeddingClient implements EmbeddingProvider {
     input: readonly string[],
     signal?: AbortSignal
   ): Promise<number[][]> {
-    if (signal?.aborted) {
-      throw signal.reason
+    const timeoutError = new Error('Embedding request timed out')
+    timeoutError.name = 'TimeoutError'
+    const timeoutController = new AbortController()
+    const timeoutId = setTimeout(() => {
+      timeoutController.abort(timeoutError)
+    }, this.timeoutMs)
+    const requestSignal = signal
+      ? AbortSignal.any([signal, timeoutController.signal])
+      : timeoutController.signal
+    if (requestSignal.aborted) {
+      clearTimeout(timeoutId)
+      throw embeddingAbortError(requestSignal, timeoutError)
     }
-    const timeout = AbortSignal.timeout(this.timeoutMs)
-    const requestSignal = signal ? AbortSignal.any([signal, timeout]) : timeout
     const headers: Record<string, string> = {
       accept: 'application/json',
       'content-type': 'application/json'
@@ -267,7 +288,7 @@ export class OpenAIEmbeddingClient implements EmbeddingProvider {
     if (this.apiKey) {
       headers.authorization = `Bearer ${this.apiKey}`
     }
-    let response: Response
+    let response: Response | undefined
     try {
       response = await this.transport(this.endpoint, {
         method: 'POST',
@@ -276,17 +297,25 @@ export class OpenAIEmbeddingClient implements EmbeddingProvider {
         redirect: 'error',
         signal: requestSignal
       })
+      if (!response.ok) {
+        throw new Error(
+          `Embedding request failed with HTTP ${response.status}`
+        )
+      }
+      return validateEmbeddings(
+        await readBoundedJson(response),
+        input.length
+      )
     } catch (error) {
       if (requestSignal.aborted) {
-        const abortError = new Error('Embedding request was cancelled')
-        abortError.name = 'AbortError'
-        throw abortError
+        throw embeddingAbortError(requestSignal, timeoutError)
+      }
+      if (response) {
+        throw error
       }
       throw new Error('Embedding request failed', { cause: error })
+    } finally {
+      clearTimeout(timeoutId)
     }
-    if (!response.ok) {
-      throw new Error(`Embedding request failed with HTTP ${response.status}`)
-    }
-    return validateEmbeddings(await readBoundedJson(response), input.length)
   }
 }
diff --git a/src/renderer/src/App.test.tsx b/src/renderer/src/App.test.tsx
index 382d194..f4c3529 100644
--- a/src/renderer/src/App.test.tsx
+++ b/src/renderer/src/App.test.tsx
@@ -552,7 +552,7 @@ describe('App', () => {
   it('checks for updates silently on startup and only reports a new version', async () => {
     const check = vi.fn(async () => ({
       updateAvailable: true,
-      currentVersion: '0.8.3',
+      currentVersion: '0.8.4',
       latestVersion: '0.9.0',
       releaseUrl:
         'https://github.com/mesalogo/goodbuddy/releases/tag/v0.9.0',
@@ -595,10 +595,10 @@ describe('App', () => {
   it('does not disturb startup when updates are current or offline', async () => {
     const currentResult = {
       updateAvailable: false,
-      currentVersion: '0.8.3',
-      latestVersion: '0.8.3',
+      currentVersion: '0.8.4',
+      latestVersion: '0.8.4',
       releaseUrl:
-        'https://github.com/mesalogo/goodbuddy/releases/tag/v0.8.3',
+        'https://github.com/mesalogo/goodbuddy/releases/tag/v0.8.4',
       target: {
         platform: 'windows' as const,
         arch: 'x64' as const,
diff --git a/src/shared/embedding-contracts.test.ts b/src/shared/embedding-contracts.test.ts
index ee4dac9..5e716e3 100644
--- a/src/shared/embedding-contracts.test.ts
+++ b/src/shared/embedding-contracts.test.ts
@@ -23,6 +23,16 @@ describe('embedding contracts', () => {
       latencyMs: 184,
       dimensions: 1_536
     })
+    expect(
+      embeddingDiagnosticResultSchema.safeParse({
+        status: 'available',
+        provider: 'provider',
+        model: 'slow-local-model',
+        checkedAt: 1_700_000_000_000,
+        latencyMs: 120_001,
+        dimensions: 4_096
+      }).success
+    ).toBe(true)
 
     expect(
       embeddingDiagnosticResultSchema.safeParse({
diff --git a/src/shared/embedding-contracts.ts b/src/shared/embedding-contracts.ts
index 6568a0e..6a078aa 100644
--- a/src/shared/embedding-contracts.ts
+++ b/src/shared/embedding-contracts.ts
@@ -56,7 +56,7 @@ const embeddingDiagnosticBase = {
   provider: boundedLabelSchema,
   model: boundedLabelSchema,
   checkedAt: timestampSchema,
-  latencyMs: countSchema.max(120_000)
+  latencyMs: countSchema
 }
 
 export const embeddingDiagnosticResultSchema = z.discriminatedUnion('status', [